Hello.
I moved to the USA in August 2017 with L1 visa. Earlier I was in the USA from March to April 2017 with B1 visa. As I understand I passed Substantial Presence Test for 2017. I'm Resident Alien. My question is: from what date I'm Resident Alien for Tax Return purposes? From March or from August?
Thank you in advance.

I moved to the USA in August 2017 with L1 visa. Earlier I was in the USA from March to April 2017 with B1 visa. As I understand I passed Substantial Presence Test for 2017. I'm Resident Alien. My question is: from what date I'm Resident Alien for Tax Return purposes?=======>>>>>after Feb of 2018; you are a dual status alien; you passed the substantial presence test on approximately: feb of 2018 (the 183rd day after Mar. of-2017). Your residency starting date under I.R.C. is Mar of 2017 (the first day you were present in US during the calendar year in which you passed the spt).

From March or from August?============>>>>>>from Mar. of 2017. you need to file your 2017 return as a dual status alien and file 2018 return as a US resdient.